I have 4. 10's on in my 2000 auto, I love them,I have 285 BFG's,and I feel the gearing is perfect,I can still pull a trailer without luggging,and this truck will go 110mph all day long. I had a 96 with 3. 55's,the 12V wasnt a revver,so for that truck,I think i had the right gear,but this truck has so much more snot pulling,with 3. 55's you have to go slow in 3rd,or pul at 75-80 to have enough RPM's to keep the auto happy,and stay in the power range.